In a mobile telecommunication network like a UMTS system, a primary station, for instance a Node B (or Base Station or eNB) communicates with at least one secondary station, for instance a User Equipment (or Mobile Station), by means of a plurality of channels. In order to transmit data to the primary station, a secondary station needs to request a resource to the primary station, which is then allocated. This request of allocation can be made in several ways depending on the considered channel.
In an example, in order to request a resource, it is required to indicate the amount of data to be transmitted, i.e. the data in the buffer of the secondary station. To this end, the secondary station transmits to the primary station a buffer status report indicative of the amount of data in the secondary station buffer. Thus, the primary station allocates a resource corresponding to both the capability of the network and the amount of data to be transmitted. This permits the allocation of resource to be adjusted.
However, if a message relating to an uplink resource grant is received in error, i.e. the secondary station had no use of this resource because no data is to be transmitted, or when no uplink resource grant was transmitted, this can lead to several problems. For false uplink grant, the secondary station transmits a data packet using the whole granted resource. Even if the secondary station has no data it will transmit a buffer status report using the whole of the resource indicated in the grant, for instance by completing the resource with padding bits.
Moreover, some systems use semi persistent scheduling, according to which some parameters may be configured by higher layers, and resources are granted on a periodic basis in order to match the needs of specific applications (for example uplink transmission resources every 20 ms to support VoIP). In case of false semi persistent scheduling (SPS) activation, the secondary station will periodically transmit data packets using the whole granted resource. If the secondary station has no data to transmit, it transmits a BSR, but releases the resource after a configurable number of transmissions if there is still no data to send. In both cases significant uplink interference is generated, even if the secondary station has no data to send.